The present invention relates to an active part of an electric machine. The active part has a plurality of coils which each have a sub-conductor, and a carrier part in whose grooves the coils are arranged. The coils are formed by windings of their sub-conductor, wherein the windings of a coil each have a pre-determined winding length. Furthermore, the coils have at least one winding overhang region which projects at an end face of the carrier part. Furthermore, the coils are arranged in the form of a tiered winding. The invention comprises, moreover, an electric machine having the inventive active part, and a method for producing this active part.
Electric machines, such as motors, generators and transformers, each have one or more active part(s) which are magnetically active. A motor, for example, has a stator and a rotor as the respective active part.
Coils can be inserted or wound into the stator and/or rotor of a motor or generator. The coils are then typically located in or on a laminated core. As a rule, the coils project from the end faces of the cylindrical or hollow cylindrical laminated cores and form a winding overhang of the rotor or stator. This laminated core can comprise a plurality of segments. The winding overhang of electric machines belongs to the magnetically inactive parts which do not contribute to torque formation.
The aim is therefore to keep the conductor length and the projection of the winding overhang as low as possible in order to avoid unnecessary space requirements, weight and losses.
FIG. 2 and FIG. 3 show, for example, a conventional winding overhang of a three-tiered winding, as is known from WO 2011/006693 A2. This means that here the coils 20 are located one above the other in three tiers or three levels. The three coils 20 project from a carrier part 22 on which the coils 20 are arranged in grooves. The three coils 20 each have an inclination in the tiered winding of 0 degrees (0°), 45 degrees (45°) and 90 degrees (90°) with respect to the longitudinal extension direction of the windings. The individual coils 20 initially exit perpendicularly from the end face S of the carrier part 22. The 90° coil is, as shown in the example of FIG. 1 and FIG. 2, curved perpendicularly downwards. The end of the 90° coil therefore runs parallel to the longitudinal axis of the active part 18 and the windings. The second coil, by contrast, runs at the end at a 45° angle to the end face S of the carrier part 22. The third coil, i.e. the 0° coil, runs in this sectional view in a straight line out of the end face S of the carrier part 22. The ends of each coil are produced by the arrangement of the windings of their sub-conductors 24. The arrangement of the windings of the sub-conductor 24 of a coil produces an inclined face at the end of the coil 20.
A stator of an electric machine emerges from JP H11 98740 A. The stator has a plurality of coils. Each coil has a plurality of sub-conductors. The coil is arranged in the grooves of a stator core. An end region of the coils projects at an end face of the stator core as a winding overhang. In the case of at least one coil the sub-conductors of this coil are arranged such that the coil has a V shape in the axial direction of the stator.
DE 10 2010 039 871 A1 describes an active part of an electric machine having oblique coils in the winding overhang region. The active part of the electric machine has a laminated core with an end face from which three coils project. Each of the three coils runs arcuately from the end face. Furthermore, the three coils are arranged in the winding overhang region inclined to the end face of the laminated core.
A coil of an electric machine emerges from JP H01 71946 U. The coil has a plurality of sub-conductors which are insulated from each other and are held together by a tape insulation.